Shumala’s extension, Part 4 — handling a corner

In the previous post about progress on the Shumala extension (see: http://modelingthesp.blogspot.com/2013/03/the-shumala-extension-part-3-backdrop.html ), I described re-attaching an old piece of painted backdrop to blend the new area to the old. There is a second backdrop issue, which is the fact that the Shumala extension location is the room corner at its left end. It looked like this:

     In many cases, one would cove more Masonite around this corner to conceal it. But in this particular location, there isn’t a lot of space; it isn’t entirely necessary (as I will show); and might well be more work than it is worth. Accordingly, I resorted to an old trick: just make a small-radius curve in the corner. Even a one-inch strip of, say, styrene set at a 45-degree angle would greatly soften the right-angle corner, but with drywall joint compound, one can form a smooth curve. To fill most of the corner, I took a 3/4-inch square garden stake and used a carpenter’s chisel split it into two 45-degree pieces:

The resulting two pieces are set with their 90-degree corners into the room corner, using drywall compound as an adhesive. In the photo below, I am filling the rough corners in a first coat. The corner modification is only as high as the backdrop elsewhere.

Then with successive coats, the entire corner can be faired into a smooth curve. I used a flour scoop made from a tin can, about 2.5 inches in diameter, to smooth the final contour. A larger can might work a bit better, but note that removing one end of the can eliminates the rim and permits the smooth length of the can to do its job. The scoop can be seen in the left foreground below. The rounded corner extends about 40 percent of the visible corner height.

Once several coats have been applied and sanded smooth, the corner almost disappears. I believe the key to how this works is that your eye no longer has a sharp edge to focus on, thus doesn’t focus on the corner, which of course is the point.
     Painting the sky and horizon line come next and will be shown in a future post.

Tony Thompson